Single assignment

In my earlier question about immutability, most answers assumed immutability meant only ``immutability of composite objects'' and not immutability of bindings.

So, what are the advantages, if any of single assignment (or, most accurately, run-time immutable bindings)?

I can't think of many other than ``I'm going to annotate this variable cause it really shouldn't change and if I accidently mess up I want the compiler to tell me''

Surely there are other reasons.

http://en.wikipedia.org/wiki/Static_single_assignment_form